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The radiation in the article is modulated by shielding and deshielding the neutron source. How would you modulate a neutrino?

• therein 5y ago
  That's the question and precisely what would make it novel and interesting. If you can easily modulate the source of your signal as is the case with the neutron source, it becomes as uninteresting as morse code.
• jjk166 5y ago
  Neutrino beams are produced by having a muons circulate in an accelerator with long straight sections. As the muons decay, they release neutrinos moving approximately in the same direction the muon was. You modulate the neutrinos by modulating the muon beam. The simplest way to do this is to introduce or take away muons from the beam, but another option is changing their energy. Muons have a half life of approximately 2 microseconds in their inertial reference frame, but from the standpoint of an observer, relativity can make them seem to live much longer. Decrease the energy to the beam energy such that they're moving slower and it is as if their half life decreases, causing them to decay more frequently and thus produce more neutrinos. The real issue is the detection end. Because of how little neutrinos interact with matter, you need a lot of neutrinos to pass through a detector before you can expect to see a signal, and then you need to distinguish that signal from noise.
  • mrfusion 5y ago
    Could we simply use another muon beam as a detector?
    • jjk166 5y ago
      No, neutrinos are simply a decay product, and in fact there isn't anything particularly special about a muon beam, neutrinos are a common product of many reactions, muons are just convenient because they don't cost much energy to produce and form into a beam, and they decay quickly while still living long enough to be useful. Neutrino detectors work because there is an astronomically small but non-zero chance that a neutrino emit either a Z or W boson. A Z boson can hit a nearby electron, accelerating it, or a W boson can decay into a fast moving electron, either of which can be observed in various ways. There's no way to prompt this behavior, but if you're watching enough matter while enough neutrinos are passing through, eventually you'll see some events. The number of events are proportional to how many neutrinos are passing through, so if you see a large number of events in a short period of time, you know something has sent a pulse of neutrinos. That said, you could most certainly have a muon beam neutrino detector located at the same site as a neutrino detector, allowing you to both send and receive messages. Because the neutrino beam is highly directional, it won't interfere with the detector.
• bally0241 5y ago
  You don't modulate the neutrino beam itself, but you could modulate the pion production beam. For typical neutrino beam experiments this is done with a large magnetic horn which focuses/defocuses (+/-) charged pions which then decay to (anti)neutrinos and (anti)leptons. By changing the current in the horn you could modulate the intensity of the beam to send data. Needless to say this is woefully impractical, would require an extremely large neutrino flux and detector, and would have an absolutely abysmal bit-rate. Not to mention you'd likely only be able to send messages in one direction. But it could be done. see: https://www.fnal.gov/pub/today/archive/archive_2014/today14-12-11_NutshellReadMore.html https://www.fnal.gov/pub/today/archive/archive_2014/today14-...
  • retzkek 5y ago
    It was actually demonstrated (over relatively short distance) using the MINERvA detector at Fermilab: https://arxiv.org/abs/1203.2847 https://arxiv.org/abs/1203.2847
• manpagereader 5y ago
  Why modulate it at all? Just use CW.